3
votes
2answers
59 views

Tool to force use FILE instead of RAM

I'm wondering why there is no such tool like ram2swap, similar to cpulimit in parts. E.g. There is program daemon.bin. Let's create temporary swap file ( 1 Gb ): % dd if=/dev/zero of=tmp.swap ...
1
vote
1answer
43 views

how to determine the max user process value?

Which value is correct?(or they are all correct, but which one will take effect?) $ cat /proc/sys/kernel/pid_max 32768 $ ulimit -a |grep processes max user processes (-u) 77301 $ cat ...
1
vote
0answers
34 views

Which filter configuration in kernel rate limit the outgoing packets to 1packet/sec?

Which net filter in kernel configuration other than iptables enable rate limiting on the outgoing packets on ethernet port?
3
votes
3answers
64 views

Why are file handles a scarce resource?

I feel like every tutorial I read on resource management in server settings starts by asserting that file handles are a scarce resource, and we should therefore aim to keep the list of open files to a ...
6
votes
7answers
463 views

Make disk/disk copy slower

Is there a method of slowing down the copy process on Linux? I have a big file, say 10GB, and I'd like to copy it to another directory, but I don't want to copy it with full speed. Let's say I'd like ...
2
votes
1answer
66 views

How does one determine the amount of space allocated to their command line?

How would one go about determining the amount of space allocated to their system for command lines. Is there anything else I need to be concerned with?
1
vote
1answer
223 views

Error: permission denied on key 'fs.file-nr'

# sysctl -w fs.file-nr=131072 error: permission denied on key 'fs.file-nr' Same issue when I edit /etc/sysctl.conf and try sysctl -p. Any reason why I cannot edit this value? I am on CentOS 6.5
2
votes
0answers
72 views

Limit CPU cycles inside of Xen

I'd like to run some minimum-expectation benchmarks on EC2, but I'm having an issue of high variability in my output data. Specifically, they keep giving me more CPU than I'm minimally entitled to, ...
1
vote
0answers
92 views

JVM memory limit on Linux (Debian)

When running my java program, I get following error: Exception in thread "main" java.lang.OutOfMemoryError: Requested array size exceeds VM limit I am wondering how I can increase the limits on my ...
2
votes
1answer
61 views

starts logging when the limits are hit

/etc/security/limits.conf. The file is responsible to limit resources of users/groups on a Linux server. Unfortunately, the file does not generate any logs (or the case could be that I do not really ...
5
votes
2answers
428 views

Does linux kill heavy and long running background processes after they reach some threshold?

If I start a really heavy (memory/cpu intensive) running really long running process will the OS terminate it after a period of time arbitrarily? I.e. are there any limits beyond which the OS would ...
4
votes
2answers
176 views

Externaly limiting number of CPU cores used

I need to externally limit a process/session to a certain number of cores. Are there any other possibilities than CPU affinity (I don't like the need to specify the actual cores) and cgroups (hard to ...
5
votes
1answer
1k views

How many users does Linux support being logged in at the same time via SSH?

I know Linux supports multiple users being logged in at the same time. But what's the maximum number of users that can be logged into Linux at the same time? I see there are there are 69 tty files ...
3
votes
1answer
428 views

Httpd : no space left on device

I am using Fedora 17 and over the last few days I am having an issue with my system. Whenever I try to start httpd it shows me: Error: No space left on device When I execute systemctl status ...
4
votes
2answers
809 views

What is “automatic stack expansion”?

getrlimit(2) has the following definition in the man pages: RLIMIT_AS The maximum size of the process's virtual memory (address space) in bytes. This limit affects calls to brk(2), mmap(2) and ...
2
votes
0answers
102 views

Can I limit the number of inotify watches available to a process or cgroup?

I am consistently running out of inotify resources, leading to errors along the lines of: # tail -f /some/files tail: inotify resources exhausted tail: inotify cannot be used, reverting to polling ...
1
vote
1answer
7k views

How to modify ulimit for open files on SUSE Linux Enterprise Server 10.4 permanently?

SERVER:/etc # ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited file size (blocks, -f) unlimited pending signals (-i) 96069 ...
1
vote
1answer
494 views

How to avoid 4 core limit for Ubuntu within VMWare?

I have Ubuntu installed as VM on my laptop. My laptop has quad core with HT technology making it 8 cores. Within Ubuntu VM I can only use max of 4 cores. What should I do so I can access all 8? ...
5
votes
1answer
1k views

Are limits.conf values applied on a per-process basis?

I'm tuning the nofile value in /etc/security/limits.conf for my oracle user and I have a question about its behavior: does nofile limit the total number of files the user can have open for all of its ...
3
votes
3answers
608 views

Can't add large number of rules to iptables

I made a very simple bash script (echo at start, runs commands, echos at end) to add approx 7300 rules to iptables blocking much of China and Russia, however it gets through adding approximately 400 ...
3
votes
1answer
390 views

How do you increase MAXSYMLINKS

In a python script, I am creating a bunch of symbolic links chained together. example: link1->link2->link3->.......->somefile.txt I was wondering how you can change the max number of symlinks to be ...
3
votes
2answers
2k views

How to limit ftp speed

I have multiple user on a server, they upload and download their file through FTP, sometimes some heavy transfer make high load on server, I am wondering is there any way to limit ftp speed to avoid ...
2
votes
2answers
119 views

How to constrain the resources an application can use on a linux web server

This is the situation: I have a PHP/MySQL web application that does some PDF processing and thumbnail creation. This is done by using some 3rd party command line software on the server. Both kinds of ...
8
votes
2answers
4k views

How to limit available virtual memory per process

Occasionally some processes on my GNU/Linux desktop (such as gv and gnash) use up the physical memory and cause thrashing. Since these processes aren't important, I want them to be automatically ...
3
votes
1answer
5k views

How do I increase the number of semaphore arrays in Linux?

In a Debian lenny server running postgresql, I noticed that a lack of semaphore arrays is preventing Apache from starting up. Looking at the limits, I see 128 arrays used out of 128 arrays maximum, ...
4
votes
1answer
781 views

Linux - why is kernel.shmall so low by default?

I run DB2 on Linux where I have to allocate the vast majority of memory on the machine to shared memory segments. This page is typical of the info that I've found about shmall/shmmax: ...